Summary An Airbus A319-114 (registration C-FYKR, serial number 0693) operating as Air Canada Flight596, with 84passengers and 5crew members on board, was on a scheduled flight from Las Vegas, Nevada, United States, to Montral, Quebec. The aircraft was cleared to depart Runway25R and the crew commenced a rolling take-off at 0015 Pacific standard time. Shortly thereafter, both members of the flight crew realized that the aircraft was rolling on the asphalt runway shoulder instead of on the runway centreline. At approximately 65knots indicated airspeed, the pilot flying applied left rudder to realign the aircraft with the runway centreline and completed the take-off. The flight continued to Montral where an uneventful landing was carried out. During the flight to Montral, the crew advised company dispatch of the departure occurrence. Dispatch advised the Las Vegas tower that the aircraft may have damaged some runway edge lights during the take-off roll. Three runway edge lights were found damaged. The only damage noted on the aircraft was a cut on the left-hand nose-wheel tire. There were no injuries. Ce rapport est galement disponible en franais. Other Factual Information In accordance with the provisions of Annex13 to the Convention on International Civil Aviation, the responsibility for investigating this incident was delegated to the Transportation Safety Board of Canada (TSB), representing the State of Registry. The National Transportation Safety Board (NTSB), representing the State of Occurrence, assigned an accredited representative to participate in the investigation. The operator removed the digital flight data recorder (DFDR) from the aircraft following the occurrence flight. The data were downloaded at its recorder facility in Montral and given to the TSB Engineering Laboratory for analysis. Visual meteorological conditions prevailed at the time of the take-off. Weather was not considered a factor in the occurrence. Records indicate that the aircraft was certified, equipped, and maintained in accordance with existing regulations and had no known deficiencies before the flight. The flight crew was certified and qualified for the flight in accordance with existing regulations. The captain had been working for the company since July1989. He had accumulated about 11000flight hours, including 1500hours on the Airbus319/320/321 series as captain and 1500hours as co-pilot. At the time of the incident, he was sitting in the left seat and was acting as pilot flying(PF). The co-pilot had been working for the company since November2000. He had flown approximately 10500flight hours, including 1900hours as co-pilot on the Airbus319/320/321 series. At the time of the incident, he was sitting in the right seat and was acting as pilot not flying (PNF). The flight crew was assigned to a four-day pairing starting from Toronto, Ontario, on 28January2006. It was the first time that the pilots were crewed together. They reported for work in Toronto at 1300eastern standard time for the flight to Las Vegas. The aircraft arrived at the Las Vegas McCarran International Airport (KLAS) at 2041Pacific standard time1 on the same day. The flight crew had a rest period of approximately 25hours before the scheduled return flight to Montral at 2355on January29. The flight crew arrived approximately 1hour and 15minutes before departure for the occurrence flight. It was the captain's third flight and second night flight from KLAS. It was the co-pilot's first time flying out of KLAS. The flight crew received the taxi clearance for a departure on Runway25R from the TaxiwayB (see AppendixA). As the aircraft approached the runway threshold on TaxiwayB, the flight crew received the take-off clearance, with the requirement to maintain visual separation with another aircraft that was departing ahead of them on the same runway. While the PF was aligning the aircraft to what he thought was the runway centreline, his attention was focused on the departing aircraft, which was about 5000feet down the runway, and he did not perceive the lateral displacement from the centreline. During the turn onto the runway, the PNFcompleted the before-take-off checklist by switching on the strobe lights, the runway turn-off lights, and the nose take-off light. At 0014:38, the PFinitiated a rolling take-off as recommended by the standard operating procedures manual (SOPs) and turned the aircraft onto an initial heading of 256 magnetic(M).2 At this time, the PNF was unaware that the aircraft was not aligned with the runway centreline because he was scanning the airspeed and the engine instruments as required by the SOPs. As part of the take-off procedure, the PNF must also observe that the aircraft is on the runway centreline when the thrust levers are advanced and the take-off phase is activated. After completing his internal scan, the PNF looked outside and saw a red light in front of the aircraft. He then realized that the aircraft was not on the runway centreline. He informed thePF, who had already started to correct to the left. According to the DFDR, the left correction corresponded to a six-degree heading correction and was made approximately 11seconds into the take-off run, at a speed of 64knots. At this time, the aircraft was approximately 800feet from the threshold, about 30feet to the right of the runway edge lights,3 and about 115feet right of the centreline. During the initial take-off roll, the flight crew felt a sensation similar to the aircraft going over pavement joints. This was considered unremarkable. The acceleration data downloaded from the DFDR suggested that there were no significant vibrations during the entire take-off roll. The aircraft regained the runway surface in the vicinity of the displaced threshold. At this point, the aircraft had accelerated through 113knots and the take-off was continued. The flight crew could not confirm whether they had hit any lights. However, at 0216, they advised the company dispatch of that possibility. The dispatcher informed the KLAS tower personnel who requested a runway inspection. The inspection, conducted about two hours after the event, revealed that three runway edge lights had been damaged, but all other lights were operative, with no anomalies found. The aircraft continued to Montral where an uneventful landing was carried out. The aircraft was inspected, and a cut was observed on the left-hand nose-wheel tire. The nose-wheel tire assembly was changed, and the aircraft was returned to service. According to the company flight operations manual (FOM), flight dispatch must be informed as soon as operationally suitable (by radio, ACARS,4 or telephone) of any accident, incident, or irregularity affecting flight. In this occurrence, the flight crew reported the incident to the dispatcher via ACARS at 0216, two hours after take-off. Pilots can use a variety of visual aids to ensure that an aircraft is aligned with the runway centreline: runway designation markings provided at the threshold of the runway, aircraft heading, runway centreline lights or markings, and runway edge lights. Pilots can also use the localizer signal as guidance by selecting the frequency of the departing runway localizer and making sure that the yaw bar index is centred on the primary flight display. However, this technique is usually used during take-off in low visibility and was not used in this occurrence. The SOPs list several factors that could lead to a decision to abort a take-off. Below 100knots, the decision to reject a take-off is at the captain's discretion, dependent upon take-off parameters. The SOPs state that, although all causes cannot be listed, the captain should seriously consider discontinuing a take-off if any electronic centralized aircraft monitoring (ECAM) warning is activated. If, during the take-off roll, a condition or situation that may affect the safety of flight is observed, it will immediately be voiced. If a rejected take-off is not required, the captain will call "continue." In this occurrence, there was no ECAM warning, no abnormal vibration, and the aircraft was accelerating normally. The crew continued the take-off and proceeded with the standard departure procedures. KLAS is a busy airport with an average of 1468aircraft operations per day. It has four runways: two parallel runways on the south side of the terminal buildings and two on the west side (see AppendixA). The surface of Runway25R was dry at the time of the occurrence. The runway is 14510feet long by 150feet wide and has a displaced threshold of 1397feet. It has asphalt runway shoulders capable of supporting an aircraft if it runs off the side of the runway. To provide good visual contrast with the runway, a white runway side stripe marking is painted along both sides of Runway25R (see Figure1). In accordance with Federal Aviation Administration Advisory Circular (AC) 150/5340-1J and International Civil Aviation Organization (ICAO) Annex14, Volume1, Aerodrome Design and Operations, the side stripe marking is a continuous line that is unbroken where the taxiways join the runway. In Canada, TP312, Section5.2.1.3, allows for the runway side stripe markings to be interrupted at an intersection of a runway and taxiway. In fact, all Canadian runways marked with side stripes have them interrupted at the intersection of their runways and taxiways. Runway 25R is not equipped with runway centreline lights, but has white runway centreline markings. In accordance with ICAO Annex14, Volume1, the portion of the runway before the permanently displaced runway threshold has the centreline marked with arrows. The runway is equipped with white runway edge lights except for the runway edge lights between TaxiwaysB andA2, which are red in the take-off direction due to the displaced threshold. The edge lights are raised lights except in the taxiway merge areas, where they are flush. The displaced threshold area is fed via TaxiwaysB andB1 (see AppendixA). TaxiwayA2 feeds Runway25R in the threshold marking area. On TaxiwayB, the one used during this occurrence, the taxiway centreline and the green centreline lights continue past the runway hold position along the curved taxiway centreline, across the white runway side stripe marking until it merges with the runway centreline marked by the displaced threshold arrows. At TaxiwaysB1 andA2, the taxiway centrelines continue past the runway hold position and curve onto the runway edge line. The green taxiway centreline lights for TaxiwaysA2 andB1 also continue past the runway hold position and stop at the runway edge line but do so in a straight line. The airport lighting system is usually kept at stage two intensity (out of a possible five stages) except during periods of inclement weather or unless otherwise requested. At the time of the occurrence, the lighting system was set to stage two. The TaxiwayB centreline lights were on. However, the lead-in lights from the runway hold position to the centreline on Runway25R did not catch the flight crew's attention. The investigation revealed no other adjacent lighting conditions that could give the erroneous perception that the right (north) runway edge line and lights could be the runway centreline. There are only blue taxi edge lights and green centreline taxiway lights to the north of Runway25R. There were two previously documented events during which aircraft damaged the runway edge lights on Runway25R. One additional event took place subsequent to this occurrence. Only the Air Canada event was reported. The other events were discovered when airport operations personnel conducted the required runway and taxiway inspections (see Table1). Three of the events happened at night. Air Canada considered this event a CategoryF incident. According to the FOM, CategoryF includes an accident or incident, occurring while the aircraft is in operation, which results in minor damage to an aircraft and/or injury to passengers or company personnel. This category includes damage to company or non-company property caused by the aircraft while in operation. A search of the TSB database revealed that only one similar event had been reported in the last 10years. On 24September1997, during a night take-off out of Moncton, New Brunswick, a Beechcraft200 was aligned with the runway edge lights and carried out a take-off during which one light was struck and broken. This event was not investigated, and the database did not provide enough information to identify the contributing factor(s). A similar search was done using the aviation query tool on the National Transportation Safety Board Web site with no similar events revealed.